tying down adaX to physical interfaces

[Jeremy Chadwick]

On Sat, Mar 26, 2011 at 11:54:44AM +0200, Kostik Belousov wrote:
> On Fri, Mar 25, 2011 at 10:16:43PM -0700, Jeremy Chadwick wrote:
> > Why would the disk number change on a drive swap?  This doesn't happen
> > on my Intel ICH9R controller on *any* Supermicro X7xxx or Supermicro
> > PDxxx board I have access to.
> Because the order of enumeration of controllers depends on the
> BIOS, and is not consistent among boots. Also, it changes if you
> swap controllers or insert disks into the free bays in the backplane.

Re: insert disks into free bays: it behaves as I described in my post
(paragraph #7):

http://lists.freebsd.org/pipermail/freebsd-fs/2011-March/011039.html

If someone wants me to prove it, I'll be more than happy to start
removing/inserting disks on my system here at home to show exactly what
happens (using ICH9xx with ahci.ko).  I would prove it as well with our
production machines but I'd have to physically be in the co-lo to swap
the disk.  :-)

The OP only mentioned that he was concerned with device names changing
if he swapped disks.  I have not seen hot-swapping (specifically
removal of old disk, insertion of new disk) result in the device number
increasing -- ever.

The OP didn't any mention of swapping or exchanging of controllers,
adding new ones, removing others, etc..  yeah, these could induce device
number changes, absolutely.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.               PGP 4BD6C0CB |